The 26-year-old Brazilian was top scorer in the Dutch Eredivisie last season with 34 goals and says he could move to Boro after they bid a reported £6.1million for his services.
"They are seriously interested in me," Alves told De Telegraaf. "Middlesbrough have shown this, too, with their offer.
"For such a big club and for the Premier League, I am always open and the first talks are really hopeful. That will not be the problem."